Gamoneda Formation Explained

Gamoneda Formation
Type:	Geological formation
Period:	Emsian
Age:	Emsian ~
Prilithology:	Sandstone, siltstone
Otherlithology:	Shale
Namedfor:	La Gamoneda
Region:	Tarija Department
Coordinates:	-21.5°N -64.8°W
Paleocoordinates:	-66.5°N -98.4°W
Thickness:	~340m (1,120feet)
Extent:	Cordillera Oriental

The Gamoneda Formation is an Emsian geologic formation of southern Bolivia. The approximately 340m (1,120feet) thick formation comprises marine micaceous grey siltstones and burrowed grey sandstones and shales.^{[1] [2] [3] [4] [5]}

Fossil content

The formation has provided the following fossils:

• Acastoides gamonedensis
• Australocoelia palmata
• Australospirifer hawkinsi
• Australostrophia mesembria
• Bainella (Belenops) insolita
• Cryptonella baini
• Deltacephalaspis (Deltacephalaspis) comis
• Deltacephalaspis (Deltacephalaspis) retrospina
• Deltacephalaspis (Prestalia) tumida
• Derbyina jamesiana
• Gamonedaspis scutata
• Kozlowskiaspis (Romanops) australis
• Notiochonetes falklandica
• Phacopina convexa
• Plicoplasia planoconvexa
• Protoleptostrophia concinna
• Pustulatia curupira
• Schizostylus (Curuyella) granulata
• Tarijactinoides jarcasensis
• Burmeisteria sp.
• cf. Francovichia sp.
• Calmoniidae indet.
• Eurypterida indet.

See also

• List of fossiliferous stratigraphic units in Bolivia

Further reading

• N. Eldredge and L. Branisa. 1980. Calmoniid trilobites of the Lower Devonian Scaphiocoelia Zone of Bolivia, with remarks on related species. Bulletin of the American Museum of Natural History 165(2):181-289
• P. E. Isaacson. 1977. Devonian stratigraphy and brachiopod paleontology of Bolivia. part A: Orthida and Strophomenida. Palaeontographica Abteilung A 155(5-6):133-192

Notes and References

1. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=36052 USNM loc. 20018
2. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=36056 USNM loc. 20022
3. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=36057 USNM loc. 20023
4. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=36058 USNM loc. 20024
5. http://www.fossilworks.org/cgi-bin/bridge.pl?a=collectionSearch&collection_no=36137 Scaphiocoelia Zone trilobites, Gamoneda Fm